Left panel depicts total entries in the open field of diestrous female, proestrous female and male rats (n=9–12/group) administered cocaine (0, 5, 10, or 20 mg/kg, IP). Right panel depicts time spent in the center of the open field among diestrous female, proestrous female, and male rats (n=9–12/group) administered cocaine (0, 5, 10, or 20 mg/kg, IP). * indicates significant differences from respective vehicle-administered control group.